Lock protecting devices



July 28, 1964 J. F. WELLEKENS 37,142,163

LOCK PROTECTING DEVICES Filed March 26, 1963 F|G.2. 7 FI IN VEN TOR.

John F. Wellekens United States Patent 3,142,168 LOCK PROTECTING DEVICESJohn F. Wellekens, New York, N.Y., assignor to Hotel Security SystemsCorporations, New York, N.Y., a corporation of New York Filed Mar. 26,1963, Ser. No. 268,143 4 Claims. (Cl. 70416) This invention relates to aprotective device for locks and has particular reference to a devicewhich will prevent locks from being broken open forthe purpose ofrobbery or illegal entry.

Parking meters, vending machines, storage boxes and many othercompartments are provided with doors having cylinder type locks, andthese locks are being constant ly broken open and the compartmentscontaining money and other valuables pilfered.

A method commonly used by thieves in breaking open the locks is toinsert a chisel in the keyhole of the lock and drive the chisel into thekeyhole withhammer blows. A wrench is then attached to the chisel toenable the necessary leverage to be applied to twist the chisel, and thecylinder or barrel of the lock-is thus rotated to retract the bolt andpermit of access to the interior of the compartment.

It is an object of the invention to provide a protective device whichwill prevent opening or breakage of a lock by the means above describedor possibly by other means, whereby protection for the lock and thevaluables guarded by it will result.

More particularly, the invention contemplates the provision of a lockhaving a forward extension containing a plurality of segments,rotatively mounted and defining a keyhole-like slot between them andthrough which a properly-contoured key may be inserted to reach theactual keyhole of the lock to manipulate the lock in the conventionalmanner. If a tool, such as a chisel for example, is inserted in the slotbetween the segments, such a tool will fail to reach and enter theactual keyhole of the lock and when the tool is twisted in an effort tobreak open the lock, it will merely rotate the segments. If the toolemployed happens to be thin enough to extend beyond the segments andreach the keyhole of the lock, the thinness of the tool will cause it tobreak off when the force necessary to rotate the barrel in the lock isapplied to the tool.

With these and other objects to be hereinafter set forth in view, I havedevised the arrangement of parts to be described and more particularlypointed out in the claims appended hereto.

In the accompanying drawing, wherein an illustrative embodiment of theinvention is disclosed,

FIG. 1 is an elevational view, with parts in section of a lock providedwith the improved protective device;

FIG. 2 is a view of the slot closure means for the protective device;

FIG. 3 is a sectional view, taken substantially on the line 3-3 of FIG.1, looking in the direction of the arrows;

FIG. 4 is a front elevational view of the device as seen from the leftof FIG. 1;

FIG. 5 is a front elevational view of the two segments in the device;

FIG. 6 is a side elevational view of the segments, and

FIG. 7 is a view taken on the line 7-7 of FIG. 6,

3,142,168 Patented July. 28, 1964 other known parts of the lock areomitted since they are of known construction and are operated in theusual manner by rotation'of the lock plugjthrough the use of a properlyfitting key inserted intothe keyhole 2. V The forward extension 3 of thehousing 20 of the lock is internally threaded'as indicated at 4 and acup-shaped member 5 is threaded into the extension 3 in the manner shownin FIG. 1. The cup-shaped member 5 maybe made in various lengths asdesired and it is provided with a front flange 6, and the body of thecabinetor door therefor to which the lock is fitted, is clampinglymaintained between the flange 6 and the forward end of theextension3. f

Mounted within the cup-shaped member 3 isv a pair of half-round segmentsindicated respectively at 8 and 9. These segments are made of hardenedmetal such as hardened steel and are mounted within the interior of thecup-shaped member 5 in amanne'r to permitth'e segments to be rotatedrelatively to the member 5. The segments have their opposing surfaces soshaped as to provide a slot-like opening 10 between them, simulating akeyhole and through which a lengthy, slender keyof proper shape may beinserted to reach and enter the keyhole 2 in the lock to open or closethe lock. The'segments are notched as shown at 10a to conform to keyshape. A closure plug 11 of cylindrical shape is disposed between thesegments, the same being spring-biased by means of springs 12 arrangedin pockets 13 provided in the segment 8. Said pockets communicate with arecess 14 provided in the segment 8 in which the plug 11 is located.

The spring-biased plug 11 tends to hold the segments apart, keeping themunder slight pressure, and it also acts as a closure to keep dust andmoisture out of the simulated keyhole. It is thrust aside by the entryof a key, the shank of which passes it and reaches and enters thekeyhole 2 to operate the lock 1.

The segments 8 and 9 are each formed with a forward, reduced diameterpart 15 providing a shoulder 16, and this reduced diameter part fitswithin and rotates in the opening 17 in the flange 6, as clearly seen inFIG. 1. The shoulder 16 extends behind parts of the flange 6 and thesegments are thus confined between the flange 6 and a retaining ring 18confined in a groove 19 in the cup-shaped member 5.

From the foregoing, the operation of the lock protective device will bereadily understood. The lock 1 is operated by means of a lengthy andrelatively slender key of proper contour that is inserted through theslot 10, 10a between the segments 8 and 9, to reach and enter into thekeyhole 2 of the lock 1. If the key thus entered is of the propercontour intended for the operation of the lock 1, the lock can beoperated in the normal manner.

If an attempt is made to break the look by the insertion of a chisel orsimilar tool into the slot 10, the chisel being tapered, will not passthrough theislot 10 to an extent to enable it to reach the keyhole 2.The thief will not be aware of that fact since the lock with theprotective device attached presents, as will be seen in FIG. 4, theappearance of a conventional unprotected lock. Hence when he twists thechisel by means of a wrench or other leverage tool applied to it, andthe chisel has only passed between the segments 8 and 9 and has notreached the keyhole 2, he will be merely rotating the segments withintheir container 5, leaving the lock unaffected by his efforts.

If a lengthy, slender tool is entered into the slot 10 and such toolshould be of a length to enable it to reach and enter the keyhole 2, theforce required to rotate the barrel of the lock will be found to be suchthat the slender tool will break off and the theft will thus befrustrated. Since the segments 8 and 9 are of hardened steel they willresist enlargement of the slot opening 10 by not becoming deformed, sothat an attempt to drive a relatively thick tool between the segments byenlarging the slot opening between them will be prevented.

By means of the device described, the breakage of locks for the purposeof robbery or illegal entry will be prevented.

Having thus described a single embodiment of the invention, it isobvious that the same is not to be restricted thereto, but is broadenough to cover all structures coming within the scope of the annexedclaims.

What I claim is:

1. A lock protective device comprising, a housing fitted at one end of acylinder lock, said housing containing a plurality of separate segmentsrotatively mounted in the housing and defining a keyhole-like slotbetween them whereby a tool inserted in said slot in an effort to reachand enter the keyhole of the lock behind said housing to thereby apply awrenching force to said lock will be prevented from reaching the keyholeof the lock and when such tool is rotated by applied force it willmerely rotate the segments without affecting the lock.

2. A lock protective device as set forth in claim 1, wherein thesegments are half-round hardened elements, and spring-biased means atleast partly closing the slot between the segments.

3. A lock protective device comprising, a lock casing containing lockmechanism and including a keyhole, said casing having a forwardextension, a cup-shaped member fitted into said extension, saidcup-shaped member being open at its forward end, a pair of half-roundsegments rotatively maintained in the cup-shaped member and spaced apartto define a keyhole-like slot between them in the forward end of thecup-shaped member so that a key may be passed through such slot to reachthe keyhole of the lock behind the segments, said segments beingrotative within the cup-shaped member when a tool other than a properkey is thrust between them and turned in an etfort to reach and breakthe lock.

' 4. A lock protective device provided for in claim 3, with the segmentsso spaced forwardly of the front of the lock mechanism and the spacingbetween the segments being so narrow that only a long, slender tool canbe used to reach the keyhole of the lock after passage between thesegments and with the slenderness of such tool causing it to be ofinsuflicient strength to turn the lock plug without becoming brokenwhile attempting to do so.

References Cited in the file of this patent UNITED STATES PATENTSThompson July 25, 1882 Laughlin Mar. 12, 1912 Shinn Nov. 10, 1925

3. A LOCK PROTECTIVE DEVICE COMPRISING, A LOCK CASING CONTAINING LOCKMECHANISM AND INCLUDING A KEYHOLE, SAID CASING HAVING A FORWARDEXTENSION, A CUP-SHAPED MEMBER FITTED INTO SAID EXTENSION, SAIDCUP-SHAPED MEMBER BEING OPEN AT ITS FORWARD END, A PAIR OF HALF-ROUNDSEGMENTS ROTATIVELY MAINTAINED IN THE CUP-SHAPED MEMBER AND SPACED APARTTO DEFINE A KEYHOLE-LIKE SLOT BETWEEN THEM IN THE FORWARD END OF THECUP-SHAPED MEMBER SO THAT A KEY MAY BE PASSED THROUGH SUCH SLOT TO REACHTHE KEYHOLE OF THE LOCK BEHIND THE SEGMENTS, SAID SEGMENTS BEINGROTATIVE WITHIN THE CUP-SHAPED MEMBER WHEN A TOOL OTHER THAN A PROPERKEY IS THRUST BETWEEN THEM AND TURNED IN AN EFFORT TO REACH AND BREAKTHE LOCK.